Income taxes - Additional Information (Details) - USD ($) $ in Thousands		12 Months Ended
	Mar. 27, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Deferred tax asset valuation allowance		$ 33,351	$ 12,768
Change in Valuation Allowance		20,600
Federal net operating loss carryforward		$ 104,500
Tax credit limitation on use		The federal net operating losses can be carried forward indefinitely, subject to an 80% limitation against taxable income.
Use of annual operating loss carryforwards		Sections 382 and 383, annual use of the Company’s net operating loss carryforwards may be limited in the event a cumulative change in ownership of more than 50% occurs within a three-year period.
CARES Act NOL carryover/carryback offset to taxable income.	100.00%	50.00%
Unrecognized tax benefits		$ 1,011	$ 210	$ 0
PPP Loan
Operating Loss Carryforwards [Line Items]
Proceeds from loans		700
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Orphan Drug Credit		$ 1,000
Operating Loss Carryforwards Expiration Period		2040
orphan drug credit carryforwards Expiration Period		2041
Domestic Tax Authority | Research and Development Tax Credit
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Amount		$ 1,900
California Franchise Tax Board | Research and Development Tax Credit
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Amount		$ 1,200